A labourer lay listening to a nightingale's song throughout the summer night. So pleased was he with it that the next night he set a trap for it and captured it. "Now that I have caught thee," He cried, "Thou shalt always sing to me.""We nightingales never sing in a cage." Said the bird. "Then I'll eat thee." Said the labourer. "I have always heard say that a nightingale on toast is dainty morsel.""Nay, kill me not," Said the nightingale; "But let me free, and I'll tell thee three things far better worth than my poor body." The labourer let him loose, and he flew up to a branch of a tree and said:then the song-bird flew away. 
Never believe a captive's promise. 